James g



(No Model.)

J. Gr. GREENE.

CLAMP PGB. BUTTON HOLE SEWING MACHINES.

No. 339,640` Patented Apr. 13, 1886.

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IN VENTURI WITNESSES N. PETERS, Phabljlhgmphvr. Wnshlnglom D. C.

lhvrrnb STATES Partnr trice JAMES G. GREEXE, OF ELIZABETH, NEV JERSEY, ASSIGNOR TO THE SlNGER MANUFACTURING COMPANY OF NEYV JERSEY.

CLAMP FOR BUTTON-HOLE SEWING-MACHINES.

SFLCYIGATION forming part of Letters Patent No. 339,640, dated April 13, 1886.

Application filed December 3, 1855. Serial No. iSLili'f (No model.)

To all whom may concern,.-

Be it known that I, Janes G. GREENE, a citizen ofthe United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Clamps for Button-Hole Sewing-Machines, of which the following is a speciiication, reference being had therein to the accompanying drawings.

My invention relates to that class of work clamps adap ted to open and spread the buttonhole after the work has been clamped, and it comprises certain improvements on the clamp shown by my Patent No. 319, 7 00, dated June 9, 1885, the object of the present invention being to render my clamp more convenient for use.

In thc drawings, Figure l is a plan viewof a clamp embodying my invention, and Fig. 2 is a cross-section of the same on the line 2 2, Fig. l. Eig. 3 is a plan view with the upper clamping-jaws removed; Fig. 4, a partial plan view showing the lower jaws spread apart. Fig. 5 is a side elevation of the clamp with the parts in the saine positions as iu Figs. l, and with the sprcading-lever in section. Fig. 6 is a detail view of the spreading-lever, and Fig. 7 a longitudinal section of the clamp.

A denotes the base-plate of the clamp, and B B the lower clamping plates or jaws,adapted to slide laterally on the base-plate, the lateral movements of these plates being effected by a slide, C, having inclined ribs working in inclined grooves in the I lower surfaces of the plates The upper clamping-jaws are carried by arms 1L, attached to plates or blocks G, hinged to blocks E, the latter' blocks being attached to and sliding laterally with the plates B. The jaws H are forced down against the plates B by a cross-bar, K, connected by a link or pitman, J, with a crank, t', on a small shaft, l, having its bearings in the block F, said shaft being operated by a clamping arm or lever, L, attached thereto.

All of thc parts above mentioned are, or may be, the same as in my Patent No. 319,700, hereinbcforc referred to.

In this my improved clamp the spreadinglever D is pivotcd by a pin, df, to a stationary block, of, attached to the base-plate A, said 5o lever being thus adapted to swing horizontally the clamping-jaws.

and to move the spreading-slide C back and forth by means of thcconnecting-link d,loosely attached to said slide and lever. The clamping arm or lever L is provided .with a projection, Z, which is arranged in the path of movement of a projection, d2, on the spreading-lever D as the latter lever is moved inwardL to bring the clamping-jaws together prior to releasing the work when a button-hole has been finished. This movement of the spreading-lever will 6o move the clamping-lever from the position shown by full lines to the position denoted by dotted lines in Fig. 5, and the shaft l, to which the clamping-lever is attached, will thus be turned far enough in the direction denoted by the arrow in Fig. 7 to throw the crankm over the dead-center, and the arms it and clampingiaws H will then be instantly lifted by springs 11.', placed between the block' F and arms h., to the position indicated in Fig. 7, thereby fully 7o releasing the work. Thus it will be apparent that the work will be released by operating the spreading-lever only.

In clamping the work and spreading the button-hole the clamping-lever is first turned 7 5 to the position denoted by full lines in Fig. 5, and the spreadinglever is then moved to the position shown in Fig. 4,

In order that the clamping-jaws may hold the material securely without requiring too 8o much force in clamping, it has heretofore been customary to roug'hcn their adjacent surfaces, to enable them to take a firm hold on the material, but this is objectionable when working on finely-finished leather and some other classes S5 of work, as the surface of the material is more or less marred by the roughened surfaces of To obviate this difficulty and still enable the clamping-jaws to hold the work securely, so that it will not slip when 9o the button-hole is being spread, I have provided the lower clamping-j aws, B, with shallow concave grooves b, and the upper clampingjaws, H,with convex projections 1f, tting said grooves. These grooves and projections are preferably slightly removed from the edges of the button-hole opening, so as to leave flat surfaces adjacent to said opening, the better to prevent the work from slipping when the button-hole is being spreada roo It will be obvious that the construction above referred to may be reversed by forming the concave grooves in the upper jaws, if desired.

Havin g thus described myinvention, I claim and desire to secure by Letters Patent- 1. In a button-hole Work-clamp, the combination, with the upper and lower laterallymovable clamping-jaws and a spreading-lever therefor, of an independently-movable clamping arm or lever arranged to be engaged by the said spreading-lever as the latter is moved to bring the clamping-j aws toward each other, substantially as set forth.

2. In a button-hole clamp, the combination, with the laterally movable lower clamping I jaws or plates and a spreading-lever for operating the same, of a clamping arm or lever having a projection arranged to be engaged by the spreading-lever, and upper clamping-jaws adapted to be raised to release the work when the said clamping arm or lever is operated by the said. spreading-lever, substantially as set forth.

3. In a button-hole clamp, the combination, with the laterally-movable upper and lower clamping-jaws and a spreading-lever for operating the same, of a shaft having a crank connected with the said upper clamping-jaws, said shaftbeing provided lwith a device adapted to be engaged by said spreading-lever to throw the said crank past the dead-center, andsprings for automatically lifting said upper clampingjaws to release the work when the saidcrank is thus operated, substantially as set forth.

4. In a button-holeclamp, the combination, with the laterally-movable upper and lower clamping-j aws and a spreadinglever for operating the same, of a shaft having a crank, a link and crossbar for connecting said crank with the said upper jaws, a clamping arm or lever having a projection adapted to be engaged by the spreading-lever, and springs for automatically lifting said upper jaws when the said crank is thrown past the de ad-center'by the impingementof the spreading-lever against the clamping-lever, substantially as set forth.

In testimony whereof I afx my signature in presence of two' witnesses.' p

JAMES G. GREENE.

Vitnesses:

L. B. MILLER, L. L. BURRITT. 

